1. Field of the Invention
The present invention relates to a system for a vehicle seat mounted side air bag restraint.
2. Background Art
Air bag restraint systems for a vehicle seat are used to protect vehicle occupants in the event of a side impact. Air bag restraint systems must deploy rapidly and predictably to be effective. Vehicle seats generally include a rigid frame to which urethane foam pads are secured. The seat is typically enveloped within a cover made of vinyl, cloth or leather. An air bag module, including an air bag and an inflator system, is secured to the seat frame.
The softness and elasticity of covering materials and urethane foam padding present problems for air bag deployment. As the air bag deploys, it must be channeled so that the air bag deploys through an air bag tear seam in the seat cover material. The elasticity of the seat cover material allows the air bag to expand and cause the seat cover material to bulge. This may increase air bag deployment time and result in variability in air bag deployment location. The resiliency and tendency of the foam material to deform or fragment is another problem that must be solved.
One attempt to solve the above problems is disclosed in U.S. Pat. No. 6,045,151 to Wu that employs a force concentrator that at least partially surrounds the folded air bag and concentrates or directs the force of the inflating air bag to the intended deployment site. The force concentrator avoids application of air bag deployment forces on the trim cover material to reduce the influence of the trim cover on air bag deployment. The force concentrator is an inelastic structure that surrounds or at least partially surrounds the air bag in an air bag module. This patent requires two panels to form the force concentrator. The use of two panels complicates assembly and may require that multiple pieces be joined together by seams. The Wu patent also discloses that a single panel may work on only one side of the deployment seam, but states that it must be verified that the addition of the concentrator does not induce trim cover failure elsewhere.
Applicant's invention is directed to solving the above problems as summarized below.